"It is an absolute tragedy for Africa and the people of Ethiopia to mourn such an exceptional leader who contributed to various continental and global initiatives," said Zuma.

Zuma applauded Zenawi, especially for hosting the African Union. The continental bloc has its headquarters in Ethiopia's capital, Addis Ababa.

"Our hearts and prayers are with the family of Prime Minister Zenawi, as well as the government and people of Ethiopia during this difficult time," Zuma said.

Ethiopian authorities say the long-time ruler died of an undisclosed illness on Monday, just before midnight. He was being treated out of the country.

Meles, 57, led a liberation movement and became president in 1991 after overthrowing a military junta. Since 1995, Zenawi has served as prime minister of the east African nation.

South Africa hoped Hailemariam Desalegne, Ethiopia's deputy prime minister and foreign affairs minister who is acting prime minister in the interim, would continue to maintain stability and peace in the Horn of Africa region.

International Relations spokesman Clayson Monyela said South Africa's relations with Ethiopia were excellent, as evidenced at the recent session of the Joint Ministerial Commission which was held in Addis Ababa in April.

Various bilateral agreements were signed between South Africa and Ethiopia, said Monyela.